The purpose of this project is to define the morphologic basis of intestinal motor disorders and to correlate abnormalities of structure with abnormalities of function and the clinical behavior of each disorder. We intend to study the smooth muscle and myenteric plexus of the gut in chronic idiopathic intestinal pseudo-obstruction, diabetic gastroparesis, diabetic diarrhea, idiopathic megacolon, cathartic colon, and esophageal motor disorders and the extraintestinal nervous system in diabetic gastroenteropathy. Tissue made available via surgery or autopsy will be systematically studied by conventional light microscopy, silver staining of longitudinal sections of the myenteric plexus, electron microscopy and immunohistochemistry. In many cases, patients will have been clinically evaluated by the investigators and we will be able to correlate the radiographic and/or esophageal manometric findings with the pathologic findings. In other cases, tissue will be sent from outside institutions accompanied by appropriate records and x-rays. Our aim is to define the nature and distribution of morphologic abnormalities (if present) in order to achieve a better understanding of pathogenesis and to establish diagnostic criteria by which pathologists will be able to diagnose some of these disorders.